The present application claims the benefit of the filing date of Provisional Application Ser. No. 60/238,939, filed Oct. 10, 2000, now pending (hereby incorporated by referenced for all purposes).
The present invention relates generally to a testing apparatus and method, and more particularly, to such an apparatus and method for generating a detectable indicator gas used in a variety of testing procedures. The indicator gas generated by the inventive apparatus may be used, for example, to fit test respiratory protection devices; as an air flow indicator industry; or as a leak detection indicator for negative and positive pressure enclosures.
Prior art gas-sampling devices are provided with a manual pump to draw gas into a compartment containing a chemical substance. When the chemical and the gas are mixed, a reaction occurs which effects a coloration indicating the level, amounts, or constituents of the gas sample. Alternatively, prior art respirator fit testing devices have been used with a similar manual pump. The pump is manually operated to draw air into the container and to expose the chemical stored in the device, thereby generating a chemical reaction that produces a gaseous-vapor or smoke. The smoke generated is dispersed in the vicinity of the wearer of the respiratory protection device such that, if the respiratory protection device does not provide the necessary seal, the smoke is detected by the wearer.
Prior art respiratory fit testing devices employ an elongated, glass tube equipped with a hollow, middle compartment for containing the chemical substance and ends which may be broken to introduce ambient air into the container. The glass tube is attachable to a hand pump, such as a hand bulb or squeeze bulb, than is manually operated to force or draw air past the chemical substance, thereby generating a chemical reaction to produce “smoke.”